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Register a new userSurface structures of tellurium on Si(111)-(7x7) studied by low-energy electron diffraction and scanning tunneling microscopy
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Added by
Felix L\\\"upke M.Sc.
Publication date
2018
fields
Physics
and research's language is
English
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The Te-covered Si(111) surface has received recent interest as a template for the epitaxy of van der Waals (vdW) materials, e.g. Bi$_2$Te$_3$. Here, we report the formation of a Te buffer layer on Si(111)$-$(7$times$7) by low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). While deposition of several monolayer (ML) of Te on the Si(111)$-$(7$times$7) surface at room temperature results in an amorphous Te layer, increasing the substrate temperature to $770rm,K$ results in a weak (7$times$7) electron diffraction pattern. Scanning tunneling microscopy of this surface shows remaining corner holes from the Si(111)$-$(7$times$7) surface reconstruction and clusters in the faulted and unfaulted halves of the (7$times$7) unit cells. Increasing the substrate temperature further to $920rm,K$ leads to a Te/Si(111)$-(2sqrt3times2sqrt{3})rm R30^{circ}$ surface reconstruction. We find that this surface configuration has an atomically flat structure with threefold symmetry.
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This paper has been withdrawn by first author KM Seemann.
We report an experimental refinement of the local charge density at the Si (111) 7x7 surface utilizing a combination of x-ray and high energy electron diffraction. By perturbing about a bond-centered pseudoatom model, we find experimentally that the adatoms are in an anti-bonding state with the atoms directly below. We are also able to experimentally refine a charge transfer of 0.26(4) e- from each adatom site to the underlying layers. These results are compared with a full-potential all-electron density functional DFT calculation.
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